The lawsuit argues that the U.S. Constitution’s Supremacy Clause “prohibits Illinois, Chicago, Cook County, and their officials from obstructing the Federal Government’s ability to enforce laws that Congress has enacted or to take actions entrusted to it by the Constitution.”

The Justice Department sued the state of Illinois, the city of Chicago and other local jurisdictions alleging their laws are standing in the way of the Trump administration's increased immigration enforcement in the area,

The Trump administration has sued Illinois and Chicago, alleging its laws are impeding on federal efforts to enforce immigration laws.